This invention relates generally to packing glands for oil well pumps and more particularly to improvements to such glands to prevent the leaking of oil therefrom.
In the typical oil well pump, a sucker rod extends down into the well pipe and is reciprocated in the well pipe to draw out the oil. The sucker rod is driven by a counterweighted arm pivoted by a drive motor. The sucker rod is connected to the arm by a polish rod which passes into the well pipe through a packing gland. At the top of the well, just under the packing gland, is a Tee which connects the well pipe to a discharge line that carries the output of the well to a collecting point or sump. According to older techniques the oil discharge lines were under relatively small pressure because the sumps were open. Now, due to environmental protection requirements, energy conservation, and other factors, many discharge oil lines feed closed sumps or other storage facilities and must deliver the oil under substantial pressures.
Furthermore, many wells are now being injected with steam to increase their productivity. This not only makes the oil less viscous, but it frequently causes the oil to be delivered to the surface under substantial pressure.
Even before the conditions of increased discharge line pressures occurred, leaking in packing glands was a problem. Not only was valuable oil being wasted and a messy condition being created around most well heads, but continuous maintenance was required to minimize the leaking. Now increased pressures are being created in discharge lines, and the conservation of oil and avoidance of bad environmental conditions are important considerations, this problem has been greatly accentuated.
Prior to my invention, various improvements were attempted to minimize packing gland leaks. In general, these were directed toward providing a tighter seal between the gland packing and the polish rod. Since the polish rod must continuously reciprocate in the gland, however, this approach results in faster wearout of the packing in the packing gland and increased drive motor laod because of the friction between the polish rod and the packing.
A need, therefore, exists for a better way to control oil leakage from the well packing gland.
It is a major object of my invention to provide a leak retreiver mechanism which controls packing gland leakage oil and permits increased packing gland leakage without adverse effects.
It is also an important object of my invention to control the leakage oil by retrieving it rather than preventing its leakage.
Another object of my invention is to provide a packing gland leak retriever for oil wells that is operated by the drive system of the well pump and, therefore, requires no separate power source.
A further object of my invention is to provide a packing gland leak retriever of the type described which can be installed outside of the well pipe and packing gland with minimal modifications to the well pump apparatus and negligible well shutdown time.
Still another object of my invention is to provide a packing gland leak retriever of the type described which delivers the retrieved leakage oil back into the well discharge line.
Still a further object of my invention is to provide a packing gland leak retriever of the type described which is inexpensive and relatively maintenance free.